Answer: The sample mean = $3.59 and the margin of error is 0.23.
Explanation:
The confidence interval for mean is given by :-
, where
is the sample mean and E is the margin of error .
Given : A 95% confidence interval for the average price of a gallon of regular gasoline in your state is from $3.36 to $3.82.
Lower limit of confidence interval :
(1)
Upper limit of confidence interval :
(2)
Adding (1) and (2) , we get

From (1) , we have

Hence, the sample mean = $3.59 and the margin of error is 0.23.